How do you make keychains out of cardboard?

first find a kind of cardboard you use a lot in your house. example: a specific kind of cereal that you have a lot. then find a ruler and cut out a square (could be rectangle). then find a piece of paper (better white) and cut out two pieces that are ruffly the same size as the cardboard. then draw on them in pencil crayon so it is very light. then right a little saying like ur my bud. or Jesus loves me. once your done cover the shape with a clear tape to make it stong and so that it won't skrape. after that you can drill a hole in the corner or use a hole punsher but since it is thick the hole punsher might not work.any way you want make a hole in the top corner and buy a keychain ring at a craft store.put it on through the hole and sell give or keep it for yourself.